Kerry to attend Rome, London talks on Islamic State, Syria | Reuters

WASHINGTON U.S. Secretary of State John Kerry will attend a gathering in Rome on Tuesday of countries fighting Islamic State militants and then go on to London the next day for an aid conference on Syria, the State Department said.

Kerry makes the trip as the United Nations is having trouble starting indirect peace talks between the Syrian government and opposition to try to end the nearly five-year civil war in which more than 250,000 people have been killed.

The so-called proximity talks, in which U.N. envoy Staffan de Mistura would speak separately to each side in Geneva, were supposed to begin on Monday but were postponed amid uncertainty about whether the opposition would attend.

Syria's opposition High Negotiations Committee would go to Geneva to meet de Mistura, an independent activist said on Friday on behalf of the group, but it would not get involved in negotiations with the Syrian government.

Kerry has pushed hard for the talks to try to end the conflict, which has been intensified by the Islamic State militant group's seizure of swathes of Syrian territory.

Tuesday's meeting in Rome "will review progress to date and discuss ways to further intensify commitments across all lines of effort to degrade and defeat" the militant group, State Department spokesman John Kirby said in a statement.